KR20210106591A - Manufacturing method of cathod materials-solid electrolyte composite powder - Google Patents

Abstract

The present invention relates to a manufacturing method of cathode material-solid electrolyte composite powder, comprising the steps of: preparing a lithium (Li) precursor, a manganese (Mn) precursor, and a phosphorus (P) precursor to form a cathode material; preparing a lithium (Li) precursor, an aluminum (Al) precursor, a titanium (Ti) precursor, and a phosphorus (P) precursor to form a solid electrolyte; forming a precursor solution by mixing the precursors for forming the cathode material and the precursors for forming the solid electrolyte in a solvent; generating droplets from the precursor solution; spraying the droplets into a preheated reactor; and collecting the cathode material-solid electrolyte composite powder produced by pyrolysis of the droplets in the reactor in a collector. According to an embodiment of the present invention, since the grinding process and the coating process are unnecessary, the manufacturing process is simple, and the production cost and time can be reduced. Also a spherical shape can be made, and the interfacial resistance can be lowered because the cathode material and the solid electrolyte are complexed.

Description

The cathode material-solid electrolyte composite powder manufacturing method {Manufacturing method of cathod materials-solid electrolyte composite powder}

The present invention relates to a method for manufacturing a composite powder that can be used as a cathode material in the all-solid-state battery field, and more particularly, a grinding process and a coating process are unnecessary, so the manufacturing process is simple, the production cost and time can be reduced, and the spherical shape It relates to a method of manufacturing a cathode material-solid electrolyte composite powder having a shape of

An electrolyte, one of the main components of a secondary battery, serves as a passageway for ions in the battery. Electrolytes include liquid electrolytes and solid electrolytes.

Currently, the most widely used liquid electrolyte uses a salt dissolved in an organic solvent and has excellent ionic conductivity, but there is a risk of combustion or explosion due to ignition or ignition due to the use of a combustible organic solvent. In particular, the flammability of such a liquid electrolyte may be a burden factor in electric vehicle applications.

The solid electrolyte mainly uses flame-retardant materials and is stable at high temperatures. In addition, since the solid electrolyte acts as a separator, a conventional separator is unnecessary, and thus a battery can be manufactured in the form of a thin film.

In the conventional battery using liquid electrolyte, since the liquid electrolyte is impregnated in the positive electrode plate, the bonding between the positive electrode material and the electrolyte is excellent, whereas the solid electrolyte is not impregnated in the positive electrode plate. Mixing must be preceded. In this case, it is difficult to bond the positive electrode material to the solid electrolyte by simple mixing, so that the electrical resistance is increased.

In general, a composite having a core-shell structure is synthesized through a multistage process by a liquid phase process. Since a large amount of organic materials for synthesizing the powder constituting the core is used in the multi-step process by the liquid phase process, there are problems such as residual organic matter and low crystallinity due to low-temperature synthesis. In addition, there is a problem in that expensive reagents such as alkoxides must be used to form the coating layer of the shell part. In addition, mass production is difficult because the process is complicated. Therefore, in order to develop a new material having a high-purity cathode material-solid electrolyte core-shell structure, it is necessary to develop high-temperature synthesis technology.

Republic of Korea Patent Publication No. 10-1460113

The problem to be solved by the present invention is that the grinding process and the coating process are unnecessary, so the manufacturing process is simple, the production cost and time can be reduced, it has a spherical shape, and the interfacial resistance can be lowered because the cathode material and the solid electrolyte are complexed. To provide a method for producing a cathode material-solid electrolyte composite powder.

The present invention provides a step of preparing a lithium (Li) precursor, a manganese (Mn) precursor, and a phosphorus (P) precursor to form a cathode material, and a lithium (Li) precursor, aluminum (Al) to form a solid electrolyte Preparing a precursor, a titanium (Ti) precursor, and a phosphorus (P) precursor, and mixing the precursors for forming the cathode material and the precursors for forming the solid electrolyte in a solvent to form a precursor solution; , generating droplets from the precursor solution, spraying the droplets into a pre-heated reactor, and collecting the cathode material-solid electrolyte composite powder produced by thermal decomposition of the droplets in the reactor in a collector Provided is a method for preparing a cathode material-solid electrolyte composite powder.

The lithium (Li) precursor is selected from the group consisting of acetate, nitrate, carbonate, chloride, hydrate and oxide containing lithium (Li) as a component It may contain one or more precursors.

The manganese (Mn) precursor may include one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates and oxides containing manganese (Mn) as a component.

The phosphorus (P) precursor may include at least one precursor selected from the group consisting of phosphoric acid, phosphorous oxide, and chloride containing phosphorus (P) as a component.

The aluminum (Al) precursor may include one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates, and oxides containing aluminum (Al) as a component.

The titanium (Ti) precursor may include a precursor including at least one material selected from the group consisting of titanium oxide and alkoxide containing titanium (Ti) as a component.

It is preferable that the total concentration of the precursors for forming the cathode material is 0.02 to 1M.

It is preferable that the concentration of the total of the precursors for forming the solid electrolyte is 0.02 to 1M.

The cathode material may be _{LiMnPO 4 .}

The solid electrolyte may be a Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5)-based compound.

The temperature in the reactor is 700 to 1200 ℃, it is preferable that the reactor is composed of air or oxygen atmosphere.

According to the present invention, since the composite powder is manufactured from the droplets, the grinding process and the coating process are unnecessary, so that the manufacturing process is simple and the production cost and time can be reduced. In addition, since the cathode material and the solid electrolyte are complexed, the interfacial resistance can be lowered.

The cathode material-solid electrolyte composite powder prepared by using the spray pyrolysis process according to the present invention has a very small particle size, has a spherical shape, and can achieve high conductivity.

According to the present invention, since the powder is manufactured through a single process, there is no need for a grinding process and a coating process essential in the conventional process, so the total process time can be shortened, and the mixing of impurities, composition change, and the like can be suppressed.

1 is a view showing an example of an apparatus for manufacturing a cathode material-solid electrolyte composite powder.
2 is a view showing an X-ray diffraction (XRD) pattern of a cathode material-solid electrolyte composite powder prepared according to an experimental example.
3 is a view showing an X-ray diffraction (XRD) pattern of a cathode material powder prepared according to a comparative example.
4 and 5 are transmission electron microscope (TEM) pictures of the cathode material-solid electrolyte composite powder prepared according to Experimental Example.
6 is a diagram showing the results of Dot mapping analysis of the cathode material-solid electrolyte composite powder.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are provided so that those of ordinary skill in the art can fully understand the present invention, and may be modified in various other forms, and the scope of the present invention is limited to the examples described below it's not going to be

When it is said that any one component "includes" another component in the detailed description or claims of the invention, it is not construed as being limited to only the component, unless otherwise stated, and other components are further added. It should be understood as being able to include

The method for producing a cathode material-solid electrolyte composite powder according to a preferred embodiment of the present invention comprises the steps of preparing a lithium (Li) precursor, a manganese (Mn) precursor, and a phosphorus (P) precursor so as to form a cathode material; Preparing a lithium (Li) precursor, an aluminum (Al) precursor, a titanium (Ti) precursor, and a phosphorus (P) precursor to form an electrolyte, and the precursors and the solid electrolyte for forming the cathode material Forming a precursor solution by mixing the precursors to make it into a solvent, generating droplets from the precursor solution, spraying the droplets into a pre-heated reactor, and the droplets are pyrolyzed in the reactor. and collecting the cathode material-solid electrolyte composite powder in a collector.

The lithium (Li) precursor is selected from the group consisting of acetate, nitrate, carbonate, chloride, hydrate and oxide containing lithium (Li) as a component It may contain one or more precursors.

The manganese (Mn) precursor may include one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates and oxides containing manganese (Mn) as a component.

The phosphorus (P) precursor may include at least one precursor selected from the group consisting of phosphoric acid, phosphorous oxide, and chloride containing phosphorus (P) as a component.

The aluminum (Al) precursor may include one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates, and oxides containing aluminum (Al) as a component.

The titanium (Ti) precursor may include a precursor including at least one material selected from the group consisting of titanium oxide and alkoxide containing titanium (Ti) as a component.

It is preferable that the total concentration of the precursors for forming the cathode material is 0.02 to 1M.

It is preferable that the concentration of the total of the precursors for forming the solid electrolyte is 0.02 to 1M.

The cathode material may be _{LiMnPO 4 .}

The solid electrolyte may be a Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5)-based compound.

The temperature in the reactor is 700 to 1200 ℃, it is preferable that the reactor is composed of air or oxygen atmosphere.

Hereinafter, a method for producing a cathode material-solid electrolyte composite powder according to a preferred embodiment of the present invention will be described in more detail.

In the present invention, a new technique for mass production of a cathode material-solid electrolyte composite powder using a spray pyrolysis process is presented. In the present invention, the complex liquid phase process of synthesizing the conventional cathode material-solid electrolyte composite powder can be replaced with a simple spray pyrolysis process, and in the production of a conventional cathode plate for an all-solid battery, the cathode and the solid electrolyte are mixed by simple mixing. It is possible to solve the problem of not being able to easily contact each other.

1 is a view showing an example of an apparatus for manufacturing a cathode material-solid electrolyte composite powder.

Referring to FIG. 1 , a lithium (Li) precursor, a manganese (Mn) precursor, and a phosphorus (P) precursor are prepared in order to form a cathode material including lithium (Li), manganese (Mn) and phosphorus (P) components. . The cathode material preferably contains lithium (Li), manganese (Mn) and PO ₄ in a molar ratio of 1:1:1, and in consideration of this, the content of the lithium (Li) precursor, the manganese (Mn) precursor and the phosphorus (P) precursor Weigh and prepare The cathode material may be _{LiMnPO 4 .} The lithium (Li) precursor, the manganese (Mn) precursor, and the phosphorus (P) precursor are preferably water-soluble precursors. When an insoluble precursor is used, it is preferable to sufficiently disperse it using an ultrasonic disperser, a high-pressure disperser, or the like to ensure dispersion stability. The lithium (Li) precursor is selected from the group consisting of acetate, nitrate, carbonate, chloride, hydrate and oxide containing lithium (Li) as a component It may be one or more precursors. For example, the lithium (Li) precursor may include _{LiNO 3 .} The manganese (Mn) precursor may be one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates and oxides containing manganese (Mn) as a component. For example, the manganese (Mn) precursor may include Mn(NO ₃ ) ₂ . The phosphorus (P) precursor may be one or more precursors selected from the group consisting of phosphoric acid, phosphorous oxide, and chloride containing phosphorus (P) as a component. For example, the phosphorus (P) precursor may include P ₂ O ₅ .

In order to form a solid electrolyte containing lithium (Li), aluminum (Al), titanium (Ti) and phosphorus (P) components, a lithium (Li) precursor, an aluminum (Al) precursor, a titanium (Ti) precursor, and phosphorus ( P) Prepare the precursor. In the solid electrolyte, Li, Al, Ti and (PO ₄ ) ₃ preferably form a molar ratio of 1+x, x, 2-x, 1, and in consideration of this, a lithium (Li) precursor, an aluminum (Al) precursor, It is prepared by weighing the content of the titanium (Ti) precursor and the phosphorus (P) precursor. The solid electrolyte may be a Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5) compound. The lithium (Li) precursor, the aluminum (Al) precursor, the titanium (Ti) precursor, and the phosphorus (P) precursor are preferably water-soluble precursors. When an insoluble precursor is used, it is preferable to sufficiently disperse it using an ultrasonic disperser, a high-pressure disperser, or the like to ensure dispersion stability. The lithium (Li) precursor is selected from the group consisting of acetate, nitrate, carbonate, chloride, hydrate and oxide containing lithium (Li) as a component It may be one or more precursors. For example, the lithium (Li) precursor may include _{LiNO 3 .} The aluminum (Al) precursor may be one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates, and oxides containing aluminum (Al) as a component. For example, the aluminum (Al) precursor may include Al(NO ₃ ) ₃ . The titanium (Ti) precursor may be a precursor including at least one material selected from the group consisting of titanium oxide and alkoxide containing titanium (Ti) as a component. For example, the titanium (Ti) precursor may include TTIP (Ti[OCH(CH ₃ ) ₂ ] ₄ ). The phosphorus (P) precursor may be one or more precursors selected from the group consisting of phosphoric acid, phosphorous oxide, and chloride containing phosphorus (P) as a component. For example, the phosphorus (P) precursor may include P ₂ O ₅ .

Precursors (lithium (Li) precursor, manganese (Mn) precursor, and phosphorus (P) precursor) for forming the cathode material and precursors for forming a solid electrolyte (lithium (Li) precursor, aluminum (Al) precursor, A precursor solution is formed by mixing a titanium (Ti) precursor and a phosphorus (P) precursor) in a solvent. Precursors (lithium (Li) precursor, manganese (Mn) precursor, and phosphorus (P) precursor) for forming the cathode material are mixed in a solvent, and precursors for forming a solid electrolyte (lithium (Li) precursor, aluminum (Al) precursor, titanium (Ti) precursor, and phosphorus (P) precursor) may be mixed in a solvent and then mixed to form a precursor solution. The solvent may be water (H ₂ O) or the like. It is preferable that the total concentration of the precursors for forming the cathode material is about 0.02 to 1M. It is preferable that the concentration of all precursors for forming the solid electrolyte is about 0.02 to 1M.

Droplets are generated from the precursor solution. The droplets may be generated through an ultrasonic atomizer, an air nozzle atomizer, an ultrasonic nozzle atomizer, a filter expansion aerosol generator (FEAG), a disk-type droplet generator, and the like. The size of the droplet greatly affects the size of the composite powder to be produced. Therefore, the size of the droplet is preferably controlled to be 0.1 to 100 μm.

The droplets are sprayed into a preheated reactor. The droplets may be moved to the reactor using a carrier gas. The carrier gas is preferably at least one gas selected from the group consisting of argon (Ar), oxygen, air and nitrogen depending on the reaction system.

In the reactor, the droplets pass through the reactor and are pyrolyzed. The temperature and reaction time in the reactor may be controlled through the flow rate of the carrier gas. The residence time in the reactor is preferably controlled to be 1 to 60 seconds depending on the size of the droplets and the reaction rate of the reactants. It is preferable to do If the carrier gas flow rate is too low, the process yield may be lowered due to poor transport of droplets.

It is preferable that the temperature in the said reactor is about 700-1200 degreeC. At a low reaction temperature, amorphous particles may be prepared, and at a high temperature, the crystallinity of the prepared particles may be increased. The atmosphere in the reactor is preferably an oxidizing atmosphere (eg, air or oxygen atmosphere). The reactor is preferably made of glass or alumina material depending on the environment of use.

Although the residence time is short in this reactor, by heating, the solvent and organic components contained in the droplets are decomposed, leaving only the components of the desired composition. At this time, the positive electrode material particles having crystallinity push the solid electrolyte composition having an amorphous phase to the particle surface, and finally, a powder in which the positive electrode material particle surface is coated with a solid electrolyte having an amorphous phase is synthesized.

The droplets sprayed into the reactor are reacted by pyrolysis and have a spherical shape to lower the degree of freedom, and since one powder is formed from one droplet, a fine-sized composite powder is produced without the need for additional milling and classification processes. is synthesized

The cathode material-solid electrolyte composite powder produced by passing through the reactor is collected in a collector. The collector may be a recovery device using a bag filter, a recovery device using a cylindrical filter paper, or a recovery device using a cyclone.

The cathode material-solid electrolyte composite powder prepared by the present invention is a spherical particle having a particle size of 100 nm to 2 μm. For the cathode material, the cathode material _{may be LiMnPO 4} , and the solid electrolyte may be a Nasicon-type oxide, LATP (Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5)-based compound.

The cathode material-solid electrolyte composite powder prepared according to a preferred embodiment of the present invention exhibits a uniform particle size distribution and maintains a perfect spherical shape, and has a particle shape that cannot be obtained in the conventional melt-cooling process. The cathode material-solid electrolyte composite powder produced through this can realize high ionic conductivity.

According to the present invention, a smaller number of unit processes are required compared to the existing commercially available melt-cooling process, and a pulverization process that causes defects in the properties of the powder is not required.

According to the present invention, it is possible to reduce the sintering temperature and time during sintering compared to the melt-quenching method, which is an existing commercial manufacturing method, thereby preventing compositional destruction due to lithium volatilization, and through the existing melt-quenching method It is possible to omit the crystallization, crushing, and drying processes that were essential during manufacturing, and it is possible to unify the manufacturing process and save process time and cost.

According to the present invention, by synthesizing the cathode material-solid electrolyte composite powder in a single process using the spray pyrolysis process, the synthesis time can be shortened, the process yield can be increased, and the process cost can be lowered through a simple process.

Hereinafter, experimental examples according to the present invention are specifically presented, and the present invention is not limited to the experimental examples presented below.

<Experimental example>

_{LiNO 3 4.22 g, a lithium (Li) precursor, Mn(NO 3} ) ₂ 17.76 g, a manganese (Mn) precursor, in order to form a cathode material containing lithium (Li), manganese (Mn) and phosphorus (P) components; Phosphorus (P) precursor P ₂ O ₅ 4.35 g was prepared.

In order to form a solid electrolyte containing lithium (Li), aluminum (Al), titanium (Ti) and phosphorus (P) components, LiNO ₃ 1.89 g as a lithium (Li) precursor, Al (NO as an aluminum (Al) precursor) ₃ ) _{3 1.09 g, TTIP (Ti[OCH(CH 3} ) ₂ ] ₄ ) as a titanium (Ti) precursor (Ti[OCH(CH 3 ) 2 ] 4 ) 4.89 ml and P ₂ O ₅ 2.06 g as a phosphorus (P) precursor were prepared.

Precursors (lithium (Li) precursor, manganese (Mn) precursor, and phosphorus (P) precursor) for forming the cathode material and precursors for forming a solid electrolyte (lithium (Li) precursor, aluminum (Al) precursor, A precursor solution was formed by dissolving a titanium (Ti) precursor and a phosphorus (P) precursor) in water (H _{2 O).}

Droplets were generated from the precursor solution. The droplets were generated through an ultrasonic atomizer.

The droplets were sprayed into a preheated reactor. The droplets were moved to the reactor using a carrier gas, and air gas was used as the carrier gas. The flow rate of the carrier gas was controlled to 10 L/min. The temperature in the reactor was about 900°C.

The cathode material-solid electrolyte composite powder produced by passing through the reactor was collected in a collector.

The composite powder thus prepared is a composite of a cathode material having a composition of _{LiMnPO 4} and a solid electrolyte having a composition of _{Li 1.3} Al _0.3 Ti _1.7 (PO ₄ ) _{3 ).}

Comparative examples are presented so that the characteristics of the experimental examples can be more easily understood, and the comparative examples below are merely presented to aid understanding and are not prior art of the present invention.

<Comparative example>

4.22 g of LiNO ₃ , 17.76 g of Mn(NO ₃ ) ₂ , and 4.35 g of P ₂ O ₅ were dissolved in water to form a precursor solution.

Droplets were generated from the precursor solution. The droplets were generated through an ultrasonic atomizer.

The droplets were sprayed into a preheated reactor. The droplets were moved to the reactor using a carrier gas, and the carrier gas was air (Arr) gas. The flow rate of the carrier gas was controlled to 10 L/min. The temperature in the reactor was about 900°C.

The cathode material powder produced by passing through the reactor was collected in a collector.

2 is a view showing an X-ray diffraction (XRD; X-ray diffraction) pattern of the cathode material-solid electrolyte composite powder prepared according to Experimental Example.

Referring to FIG. 2 , it was found to have an XRD pattern in which _{crystalline LiMnPO 4 and amorphous were mixed.} It is estimated that the amorphous compound is a LATP (Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5)-based compound constituting a solid electrolyte.

3 is a view showing an X-ray diffraction (XRD) pattern of a cathode material powder prepared according to a comparative example.

Referring to FIG. 3 , it is determined that _{crystalline LiMnPO 4 is synthesized.}

4 and 5 are transmission electron microscope (TEM) pictures of the cathode material-solid electrolyte composite powder prepared according to Experimental Example.

4 and 5 , it appears that the amorphous solid electrolyte is coated on the crystalline cathode material (LiMnPO _{4 ).}

6 is a diagram showing the results of Dot mapping analysis of the cathode material-solid electrolyte composite powder.

Referring to FIG. 6 , in the composition of the amorphous LATP, Ti is distributed on the surface, and _{Mn of LiMnPO 4} is distributed inside LATP(Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ ( 0.1≤x≤0.5) is determined to be coated on the surface of _{LiMnPO 4 .}

As mentioned above, although preferred embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various modifications are possible by those skilled in the art.

Claims (11)

preparing a lithium (Li) precursor, a manganese (Mn) precursor, and a phosphorus (P) precursor to form a cathode material;
preparing a lithium (Li) precursor, an aluminum (Al) precursor, a titanium (Ti) precursor, and a phosphorus (P) precursor to form a solid electrolyte;
forming a precursor solution by mixing precursors for forming the cathode material and precursors for forming the solid electrolyte in a solvent;
generating droplets from the precursor solution;
spraying the droplets into a preheated reactor; and
and collecting the cathode material-solid electrolyte composite powder produced by thermal decomposition of the droplets in the reactor in a collector.
The lithium (Li) precursor of claim 1, wherein the lithium (Li) precursor contains lithium (Li) as a component. ) A cathode material comprising at least one precursor selected from the group consisting of - a method for producing a solid electrolyte composite powder.
The method of claim 1, wherein the manganese (Mn) precursor comprises one or more precursors selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates and oxides containing manganese (Mn) as a component. A method for producing a cathode material-solid electrolyte composite powder.
The cathode material-solid electrolyte of claim 1, wherein the phosphorus (P) precursor comprises at least one precursor selected from the group consisting of phosphoric acid, phosphorous oxide, and chloride containing phosphorus (P) as a component. A method for producing a composite powder.
According to claim 1, wherein the aluminum (Al) precursor comprises at least one precursor selected from the group consisting of acetates, nitrates, carbonates, chlorides, hydrates and oxides containing aluminum (Al) as a component. A method for producing a cathode material-solid electrolyte composite powder.
The cathode material-solid according to claim 1, wherein the titanium (Ti) precursor comprises a precursor comprising at least one material selected from the group consisting of titanium oxide and alkoxide containing titanium (Ti) as a component. A method for producing an electrolyte composite powder.
The method of claim 1, wherein the total concentration of the precursors for forming the cathode material is 0.02 to 1M.
The method of claim 1, wherein the concentration of the total of the precursors for forming the solid electrolyte is 0.02 to 1M.
The method of claim 1, wherein the cathode material is LiMnPO ₄ .
The method of claim 1, wherein the solid electrolyte is a Li _1+x Al _x Ti _2-x (PO ₄ ) ₃ (0.1≤x≤0.5)-based compound.
The method of claim 1, wherein the temperature in the reactor is 700 to 1200° C., and the reactor is configured in an air or oxygen atmosphere.

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